You are part of a restoration ecology program that is attempting to reintroduce an endangered bird to a new habitat in Michigan, where they have been locally extinct for decades. The species went through an extreme bottleneck after they were almost wiped-out due to insecticide use in the 1960s. Maintaining what limited genetic diversity remains is an important priority, especially because disease spread from other bird species represents a major threat to the struggling populations of these birds. Captive-bred warblers destined for this site have been genotyped at a neutral marker locus “D” with two alleles, D95 and D135. The genotype counts in the captive animals are as follows: D135/D135 = 12, D135/D95 = 20, and D95/D95 = 48 2a. If all the species are used to start the new population, what is the probability that the population eventually becomes fixed for allele D95 through drift? 2b. Let’s assume the population stays the same size (as the number of introduced individuals) in the new habitat. From this as the starting point, what would be the expected decline in heterozygosity over the next ten generations? 2c. In making decisions about reintroduction strategies, there might be a tradeoff in genetic diversity of founding populations (as measured by heterozygosity) and the total number of individuals introduced. Given the genotype counts of the captive species from 1a, what is the largest population you could introduce with a starting heterozygosity of 0.5?     2d. Run this new H = 0.5 starting population through the assumptions in 2b (with the population staying the same size as the new number introduced from 2c). What is the expected decline in heterozygosity for this population over ten generations?

You are part of a restoration ecology program that is attempting to reintroduce an endangered
bird to a new habitat in Michigan, where they have been locally extinct for decades. The species went through an extreme bottleneck after they were almost wiped-out due to insecticide use in the 1960s. Maintaining what limited genetic diversity remains is an important priority, especially because disease spread from other bird species
represents a major threat to the struggling populations of these birds. Captive-bred warblers
destined for this site have been genotyped at a neutral marker locus “D” with two alleles, D95
and D135. The genotype counts in the captive animals are as follows:
D135/D135 = 12, D135/D95 = 20, and D95/D95 = 48

2a. If all the species are used to start the new population, what is the probability that the
population eventually becomes fixed for allele D95 through drift?
2b. Let’s assume the population stays the same size (as the number of introduced individuals) in
the new habitat. From this as the starting point, what would be the expected decline in
heterozygosity over the next ten generations?
2c. In making decisions about reintroduction strategies, there might be a tradeoff in genetic
diversity of founding populations (as measured by heterozygosity) and the total number of
individuals introduced. Given the genotype counts of the captive species from 1a, what is the
largest population you could introduce with a starting heterozygosity of 0.5?

 

2d. Run this new H = 0.5 starting population through the assumptions in 2b (with the population
staying the same size as the new number introduced from 2c). What is the expected decline in
heterozygosity for this population over ten generations?